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  • Wombat
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #25
(MQA style): It has long been recognized that a passband extending to 40-50 KHz. is a desirable objective, as MQA tests (and prior) have demonstrated.
It is barely established that a 20kHz filter done wrong may be spotted under laboratory conditions. There is indeed a Meridian paper so don't expect it becomes to clear.

The decoding process is simple enough; the standard passband of 22.05 KHz. (16/44.1, Red Book) is copied bit-for-bit. Any frequencies above this (ultrasonic?) band is simply compressed -and expanded during MQA playback,
It appears not very different to HE-AAC's  "SBR" component.
This (ultrasonic component) can be observed by MQA's bit-rate of 1,550? Kb/s (or thereabouts); 1411 Kb/s Red-Book and the added folding/unfolding of higher frequencies (above the prevailing noise floor). 
You can't copy content below a certain frequency. You need to filter. In this case near the audible band. On reconstruction you need another filter to reconstruct it together with the aproximation of what once was the HF content. It has already aliased components from the prior lowpassing. The lower bits are shaped off. From the second unfold on you add tons of mirroring because of lousy upsampling.
There is even more going on.

If you apply the filter correction they claim to be important to a simple noise shaped 18bit 96kHz file you don't need that nonsense and the resulting file most likely compresses better as the MQA file.
  • Last Edit: 01 October, 2017, 09:55:40 AM by Wombat
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

  • ajinfla
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #26
1) MQA starts with encoding (of the original recording). There are known flaws in many of the early (and possibly current) A/D converters. MQA begins there, i.e. correcting known (temporal-related) errors..
BS Peter/Bob. Lets see reliable audible evidence for these "flaws". This is HA not The Absolute Clown Peter/Bob.
MQA starts by allowing aliasing distortion via an audiomoron filter.

2) The original recorded Master file is used.
Wrong again, this is purely alleged fiction by MQA shills.

3) Decoding (MQA style): It has long been recognized that a passband extending to 40-50 KHz. is a desirable objective, as MQA tests (and prior) have demonstrated.
See 1) Peter Bob

As a passionate music lover, if MQA proves superior, I'll embrace it.
I must say however I'm hearing some great "sounds" even with streaming at 60-128 Kb/s (AAC) !
Anyway you look at it, Robert (Bob) Stuart and team should be applauded for  his efforts -if nothing else.
You like -you buy (or stream). If not, carry on -as usual.
pj 
Sure thing Peter Bob.
Just how does one "carry on" when music starts being originally encoded with MQA aliasing distortion?
Nice trolling btw  ;)

Loudspeaker manufacturer

  • krabapple
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #27
Leaving aside the malarkey in points #1 and #3


2) The original recorded Master file is used.

Promises , promises, Pedro.   As customers of HDtracks.com have learned, the "Master file'  can be whatever digital version the record companies supply.  Is that a flat transfer of the correct, original, two-track mixdown master tapes the artist , producer and mixing engineer created and approved back in the day?   There's certainly no guarantee.  Is Meridian being upfront about this?  Nope.

  • Last Edit: 01 October, 2017, 03:56:33 PM by krabapple

  • splice
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #28
I also thought so when it arrived, but it seems to me that it offers no DRM opportunity, i.e., no way of locking down the content to prevent copying? 


DRM doesn't have to prevent (digital) copying. In the case of MQA, the intent appears to be to prevent unauthorised reproduction at the original quality level.

... Playing it on non-[MQA|HDCD|Dolby]-aware gear would give you the music (unlike DTS-CD, mind you!), and a certain fidelity that is not outrageous - take that as "relatively speaking"...


MQA encoding provides the option to reduce the "non-MQA decoded" quality to several levels, right down to 2-bit resolution.
I suspect they leave the high bits alone to avoid blowing up equipment.

... (But "nobody" knows about everything that the MQA chips can really do? Is it conspiranoia to consider the thought that there is indeed some decryption in the chip, in case MQA catches on well enough to start delivering encrypted signal? ...

There is no magic MQA chip. There is strong encryption of part of the data stream. Follow the money. MQA didn't buy an expensive encryption product just to use as dither. 
Regards,
   Don Hills
"People hear what they see." - Doris Day

  • Porcus
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #29
MQA encoding provides the option to reduce the "non-MQA decoded" quality to several levels, right down to 2-bit resolution.

Link?

There is no magic MQA chip. There is strong encryption of part of the data stream.

You are saying that there is no hardware-based decryption in MQA-aware DACs?

  • splice
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #30
Link?

Oops. It was 4 bits, not 2. (Memory is the second thing to go with age. I forget what the first one was.)
Mans Rullgard's code analysis of the MQA Core decoder:
https://www.computeraudiophile.com/forums/topic/30572-mqa-technical-analysis/?page=9&tab=comments#comment-622783
https://www.computeraudiophile.com/forums/topic/30381-mqa-is-vaporware/?page=165&tab=comments#comment-715562

(Possible TOS violation - relates to encryption of content. Note that the code under discussion is published under an open source license.)

You are saying that there is no hardware-based decryption in MQA-aware DACs?

In a DAC with full MQA decode, there's code running in a standard processor chip (XMOS or FPGA). There is no custom chip. The same code runs in Tidal's software core decoder. Mans also looked at the "render" code, the second part of the process, that upsamples with a leaky filter. Low (processing) power DACs can only do the second "render" stage. It doesn't require DSP, just decoding the control bitstream and loading the selected filter. 
  • Last Edit: 02 October, 2017, 10:09:26 PM by splice
Regards,
   Don Hills
"People hear what they see." - Doris Day

  • Porcus
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #31
Oops. It was 4 bits, not 2. (Memory is the second thing to go with age. I forget what the first one was.)
Mans Rullgard's code analysis of the MQA Core decoder:

Thanks for enlightening me. 4 bits 44.1 kHz quality, I take the chance that I will not get hit by a TOS#8 binning for dissing that.

So in the (unlikely) event that MQA really catches on, then the RIAA will of course switch over to the least-listenable option, to win over the then-already-extinct breed of pirates who share mp3s rather than lossless?

  • allhifi
  • [*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #32
The true benefits of MQA can't be realized in short term tests like these. It requires long term relaxed listening to flesh out the lower fatigue and less digititis in MQA vs non-MQA digital streaming.
50-80yr old men will experience far less or no hot flashes and menstrual cramps associated with non-MQA smeared digital long term listening.

If that's true (" The true benefits of MQA can't be realized in short term tests like these. It requires long term relaxed listening ...") and have great doubt it is, there'e simply no point in MQA.

The SQ improvement should, literally, "hit-you-over-the-head" in distinction. There wold be simply no other reason (well there'e many reasons) for the concept to exist. And, if such a subtle Or questionable) improvement wold NOT have passed the critical listening skills of many.

I look forward to some "quality" time (lol) with MQA. I'm in no rush since I'm thoroughly enjoying whats  before me now.
We'll see (I'll see) just how much once (preferably an MQA-imbedded CD disc/similar file) a test drive can be scheduled.

pj 

  • ajinfla
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #33
If that's true (" The true benefits of MQA can't be realized in short term tests like these. It requires long term relaxed listening ...")

I always tell the truth, even when I lie
Loudspeaker manufacturer

  • allhifi
  • [*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #34
Understood. In which case I shall refer to MQA's own research (based on previous effort's) data -to be forwarded soon.

pj

  • ajinfla
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #35
Understood. In which case I shall refer to MQA's own research (based on previous effort's) data -to be forwarded soon.

pj
If you are Peter Jasz, this would be expected
Loudspeaker manufacturer

  • allhifi
  • [*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #36
In partial response to the request of "Scientific:" data, I'll offer this to start:

https://www.xivero.com/blog/hypothesis-paper-to-support-a-deeper-technical-analysis-of-mqa-by-mqa-limited/

Specifically, (5. 5.3) ; https://www.xivero.com/blog/hypothesis-paper-to-support-a-deeper-technical-analysis-of-mqa-by-mqa-limited/

This is a fine analysis of some core features and components of recoded music and auditory impressions.

This will be followed by specific research noted by the MQA patent team. In fact, I'll search (as anyone can) the MQA patent; within it will be references to the 'science' you request.

Keep in mind, although absolutely essential/crucial (technical analysis) collective subjective impressions hold far greater weight and consistency than ever-evolving scientific methodology.

 peter jasz 

  • allhifi
  • [*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #37
Understood. In which case I shall refer to MQA's own research (based on previous effort's) data -to be forwarded soon.

pj
If you are Peter Jasz, this would be expected

And who are you ? Full name please.

pj

  • ajinfla
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #38
And who are you ?
Sherlock Holmes. Retired to Florida now.
Quote
Hello there: I am Peter Jasz, managing director (Audio) at ALLIED TV & Sound, 1558 King St. E, Hamilton, Ontario, Canada. We specialize in higher-end A/V systems. I am the high-end audio guy.
I have (and continue to) search high and low for high peformance cables at reasonable cost.One of the very best I've encountered under $100 are the XLO Pro 150 (1M). A rare combination of transparancy, detail, staging and musical body define this interconnect. The Pro 125 is a cheaper version, still rather good, but the Pro 150 is definitely better. XLO also have the Pro-100 interconnect that offers greater bass extension and dimensionality, but surprisingly doesn't seem to have as good transparancy.

If you can swing the extra dollars consider the Kimber SELECT series of interconect KS-1011 (single-ended) or KS-1111 (balanced).

peter jasz
"Full" unfold will require purchase of $$ MQA $$ hardware, correct Peter?
Loudspeaker manufacturer

  • Wombat
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #39
Always a pleasure to see new members only registering to spread some pointless marketing fluff not even remotely able to deliver verifiable facts on their own.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

  • ajinfla
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #40
Now, now, remember the threads by members lamenting how poorly we treat innocent new shills and trolls, how rude, unfriendly and inconsiderate that is.
Loudspeaker manufacturer

  • Wombat
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #41
I hoped to circumvent that by using the word pleasure.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

  • bennetng
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #42
With 4bit music you can listen to silence much louder!

  • ajinfla
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #43
Loudspeaker manufacturer

  • allhifi
  • [*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #44
1) MQA starts with encoding (of the original recording). There are known flaws in many of the early (and possibly current) A/D converters. MQA begins there, i.e. correcting known (temporal-related) errors..
BS Peter/Bob. Lets see reliable audible evidence for these "flaws". This is HA not The Absolute Clown Peter/Bob.
MQA starts by allowing aliasing distortion via an audiomoron filter.

2) The original recorded Master file is used.
Wrong again, this is purely alleged fiction by MQA shills.

3) Decoding (MQA style): It has long been recognized that a passband extending to 40-50 KHz. is a desirable objective, as MQA tests (and prior) have demonstrated.
See 1) Peter Bob

As a passionate music lover, if MQA proves superior, I'll embrace it.
I must say however I'm hearing some great "sounds" even with streaming at 60-128 Kb/s (AAC) !
Anyway you look at it, Robert (Bob) Stuart and team should be applauded for  his efforts -if nothing else.
You like -you buy (or stream). If not, carry on -as usual.
pj 
Sure thing Peter Bob.
Just how does one "carry on" when music starts being originally encoded with MQA aliasing distortion?
Nice trolling btw  ;)



Wow. Your brilliance is deafening.  Before you start (or continue) with insults (that I have no issue with) but, I'd ask that you have  the decency, the manliness, to identify yourself. Hiding behind some goofy profile pic without a name is cowardly.
(Whose the troll -that won't identify himself/herself ?)

pj

  • ajinfla
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #45
Not too bright this one.
Btw Peter, that's who's or who is, not "whose". You seem a bit unbalanced, look, I'm not a Commi from Russia, if that helps your paranoia.
Just a hint, if you are going to peddle MQA like you do magic cables, etc, you may want to add a bit of detail to your profile and signature. It's frowned upon on many forums, to be a peddler without identifying as such.
Loudspeaker manufacturer

  • bennetng
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #46
In partial response to the request of "Scientific:" data, I'll offer this to start:

https://www.xivero.com/blog/hypothesis-paper-to-support-a-deeper-technical-analysis-of-mqa-by-mqa-limited/

Specifically, (5. 5.3) ; https://www.xivero.com/blog/hypothesis-paper-to-support-a-deeper-technical-analysis-of-mqa-by-mqa-limited/
Nothing more than fiddling with filters. Of course filtering can be audible if it affects audible frequency.

https://www.xivero.com/blog/hypothesis-paper-to-support-a-deeper-technical-analysis-of-mqa-by-mqa-limited/#55

I copied the png files and attached here just in case the website silently replaced or removed them.

The MQA apodizing filter starts to attenuate high frequencies at somewhere around 10-15kHz, notice the line thickness and color when compared with the original signal and steep-filtered signal.

In this post the OP obviously prefers the steep filter used in foobar's SoX plugin instead of the one used by his DAC.
https://hydrogenaud.io/index.php/topic,110058.0.html

Regardless of audibility and preferences, such kinds of filtering doesn't require specialized hardware. I found nothing innovative about MQA apart from the "revolutionary" 4-bit decoding ability which I recently read.

There are SPC decoders with user-selectable filters 10+ years ago. 8)
http://www.foobar2000.org/components/view/foo_snesapu
  • Last Edit: 05 October, 2017, 06:54:50 AM by bennetng

  • bennetng
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #47

Excellent deblurring example! Much better than MQA.

  • Wombat
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Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #48
From the second unfold on you add tons of mirroring because of lousy upsampling.

A very nice find that illustrates the effect in action at ASR while the discussion itself is pretty weightless.
  • Last Edit: 19 November, 2017, 11:05:20 AM by Wombat
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

  • bennetng
  • [*][*][*][*][*]
Re: Invite: MQA Core vs. Hi-Res Blind Test
Reply #49